Which voltage term refers to the voltage measured across the arc while welding?

• A. Load voltage
• B. Arc voltage
• C. Open circuit voltage
• D. None of the above

Answer: (B)

Arc voltage is the voltage measured across the gap between the electrode and the workpiece while the arc is burning. When you strike an arc, the supply voltage drops from its no-load value to this arc voltage, which is the stable voltage sustaining the arc. Open circuit voltage is the voltage present with no arc (no current flowing), and load voltage is the voltage the machine provides under load in a broader sense, which specifically becomes arc voltage once the arc is established. So the voltage you measure across the arc during welding is arc voltage, typically in the tens of volts range.